Loud Whining Noise from Inside the Engine near the Alternator Area

10

Asked by Nov 02, 2015 at 02:15 PM about the 2004 Toyota 4Runner SR5 4WD

Question type: Maintenance & Repair

The whining noise started 6 months ago and is getting louder.  Took it to a
mechanic who listened with a long screw driver and said it's from the
alternator bearing.  He replaced it, but the noise still there.  The noise
seems to come from inside the engine above the alternator. The noise gets
louder as the engine is rev'ed up.  What could cause such a noise inside
the engine?  Please help.  Thanks.

5 Answers

1,465

the alternator drive belt will have tensioners in it, it is the bearings in the tensioners that have gone, the technician should have noticed this on basic inspection, to replace the tensioners is a job you can do yourself and change the belt whilst you are under the hood.

1 of 1 people found this helpful.
1,465

if it is the tensioners and belt that are worn, chances are the cambelt may need changing (if fitted) a failing cambelt will result in serious damage and you may need a rebuilt motor.

50,855

If it were mine.....I would remove the serpentine belt and briefly start the engine to see if the noise is gone (do not run the engine for more than 30 seconds with the belt removed or it may overheat). If the noise remains probably the timing belt tensioner, idler or related part. If the noise disappears when the serpentine belt is removed, one of the accessories the belt drives likely has a bad bearing or other issue.

10

Bob, thank you very much for your reply. Very intelligent way of diagnosing the problem. I will pass on your advise to my mechanic. One more question: my 4Runner 4.0 engine has a timing chain, not timing belt. Is the timing chain set up the same way as a timing belt? With tensioner, idler and related parts? Thanks a lot.

1 of 1 people found this helpful.
50,855

Yes timing chains have rubbing blocks, and hydraulic tensioners. No point in getting worried about a timing chain unless it starts to make noises on start up. Good quality engine oil at the recommended grade, changed at the recommended interval and a quality oil filter will help maximize the life of the timing chain and the rest of the engine.

Your Answer

4Runner

Looking for a Used 4Runner in your area?

CarGurus has 21,713 nationwide 4Runner listings starting at $2,300.

ZIP:

Toyota 4Runner Experts

  • #1
    Kurt Burton
    Reputation
    1,230
  • #2
    azurro
    Reputation
    690
  • #3
    kbro
    Reputation
    610
View All

Related Models For Sale

Used Toyota Tacoma
581 Great Deals out of 42,138 listings starting at $2,995
Used Toyota Highlander
479 Great Deals out of 25,162 listings starting at $2,299
Used Jeep Grand Cherokee
907 Great Deals out of 71,381 listings starting at $992
Used Toyota Tundra
444 Great Deals out of 33,605 listings starting at $1,999
Used Chevrolet Tahoe
649 Great Deals out of 37,506 listings starting at $1,800
Used Toyota RAV4
912 Great Deals out of 58,859 listings starting at $1,690
Used Toyota Sequoia
139 Great Deals out of 5,297 listings starting at $2,499
Used Toyota Land Cruiser
12 Great Deals out of 1,014 listings starting at $2,650
Used Honda Pilot
439 Great Deals out of 26,211 listings starting at $1,400
Used Ford Explorer
807 Great Deals out of 62,748 listings starting at $999
Used Ford F-150
2,185 Great Deals out of 181,377 listings starting at $1,000
Used Jeep Wrangler
293 Great Deals out of 15,981 listings starting at $2,997
Used Nissan Pathfinder
319 Great Deals out of 24,187 listings starting at $2,200

Used Cars For Sale

2017 Toyota 4Runner SR5 4WD For Sale
3 Great Deals out of 2,309 listings starting at $32,887
2016 Toyota 4Runner SR5 4WD For Sale
632 listings starting at $26,480
2015 Toyota 4Runner SR5 4WD For Sale
7 Great Deals out of 278 listings starting at $24,977
2014 Toyota 4Runner SR5 4WD For Sale
8 Great Deals out of 273 listings starting at $22,775
2013 Toyota 4Runner SR5 4WD For Sale
9 Great Deals out of 294 listings starting at $18,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.